Richmond,
1. Can you "click through" the transparency to desktop on Linux? I couldn't manage that (what works on Mac/Win).
2. Be aware of a nasty resize problem with Linux + LC6.
When you are done you could compare with a solution that's fast enough for Raspi (runs also, faster, on newer MacOS X, Win7-10, newer Ubuntu):
Shaped RaspiStack #2
http://forums.livecode.com/viewtopic.php?f=76&t=26397
and please tell us your improvements.
Hermann